AutoCAD Inventor :: Dome Solid Without Hard Edges

I need to create several domed solids (as different parts) based on 2D sketches of various shapes.  I am trying to emulate domes that you might creating by pouring thick resin.

Using this forum I have found that you can do this easily using Loft to-point, then use the Conditions tab to get the dome height/shape set nicely.

The only problem is when the 2D shapes have a corner that is too sharp - then it leaves ridges on the domes - like the arrows show on this example - which is based on a simple rectangle with 0.5m radius corners:

I found one thread on this forum that said to use Delete-Face, then Patch - but the I couldn't get the patch to leave nice smoothed edges - and without bulging.